set serveroutput on  
WHENEVER SQLERROR EXIT SQL.SQLCODE

-- For each dbid and instance_number combination
-- Set first snapshot for the day as baseline
DECLARE
  l_sql_stmt VARCHAR2(4000);
BEGIN
    FOR i IN (SELECT dbid, instance_number, trunc(snap_time), min(snap_id) as snap_id
              FROM stats$snapshot a
              GROUP BY dbid, instance_number, trunc(snap_time)
              )
   LOOP 
     l_sql_stmt := 'update stats$snapshot s  
                        set s.baseline  = ''Y''
                        where s.dbid = :1 
                        and s.instance_number = :2
                        and s.snap_id = :3
                        AND nvl(s.baseline,''x'') != ''Y''
                        ';
       EXECUTE IMMEDIATE l_sql_stmt USING i.dbid, i.instance_number, i.snap_id;                     
   END LOOP;
   COMMIT;                    
END;
/



-- PURGE the data
DECLARE
  l_sql_stmt VARCHAR2(4000);
BEGIN
   FOR i in (select DISTINCT dbid, instance_number
               FROM stats$database_instance)
   LOOP
       l_sql_stmt := 'BEGIN statspack.purge(i_dbid =>  :1 '
                               || ' , i_instance_number  => :2 ' 
                               || ' , i_num_days => :3 ' 
--                               || ' , i_extended_purge => :4 '
                               || ' ); 
                      END; ';
       DBMS_OUTPUT.PUT_LINE (l_sql_stmt);
       EXECUTE IMMEDIATE l_sql_stmt USING i.dbid, i.instance_number, 120;
   END LOOP;
END;
/